Apparatus and method for power management of a computing system

ABSTRACT

A multiple graphics processing unit (GPU) based parallel graphics system comprising multiple graphics processing pipelines with multiple GPUs supporting a parallel graphics rendering process having an object division mode of operation. Each GPU comprises video memory, a geometry processing subsystem and a pixel processing subsystem. According to the principles of the present invention, pixel (color and z depth) data buffered in the video memory of each GPU is communicated to the video memory of a primary GPU, and the video memory and the pixel processing subsystem in the primary GPU are used to carry out the image recomposition process, without the need for dedicated or specialized apparatus.

CROSS-REFERENCE TO RELATED CASES

The present application is a continuation of U.S. patent applicationSer. No. 15/041,342, filed Feb. 11, 2016, which is a divisional of U.S.patent application Ser. No. 12/985,594, filed Jan. 6, 2011, which is aContinuation-in-Part (CIP) of the following US applications: applicationSer. No. 12/229,215 filed Aug. 20, 2008; application Ser. No. 12/077,072filed Mar. 14, 2008; application Ser. No. 11/890,039 filed Apr. 23,2007; application Ser. No. 11/897,536 filed Aug. 30, 2007; applicationSer. No. 11/655,735 filed Jan. 18, 2007; and application Ser. No.11/648,160 filed Dec. 31, 2006; each said patent application beingincorporated herein by reference as if set forth fully herein.

BACKGROUND OF INVENTION Field of Invention

The present invention relates generally to the field of computergraphics rendering, and more particularly, to ways of and means forimproving the performance and power and resources management of parallelgraphics rendering processes supported on multiple 3D graphicsprocessing unit (GPU) platforms associated with diverse types ofcomputing machinery.

Brief Description of the State of Knowledge in the Art

There is a great demand for high performance computer graphics systemsin the fields of product design, simulation, virtual-reality,video-gaming, scientific research, and personal computing (PC). A majorgoal of the computer graphics industry is to realize real-timephoto-realistic 3D imagery on PC-based workstations, desktops, laptops,and mobile computing devices, while efficiently using electrical powerand graphics processing resources for constantly changing applicationrequirements in any given application environment.

Currently, a number of different computer graphics processingarchitectures have been developed for PC-based computing systems.

For example, as shown in FIG. 1A, a typical PC based graphicarchitecture has an external graphics card (105) comprising a graphicsprocessing unit (GPU) and video memory. As shown, the graphic card isconnected to the display (106) on one side, and the CPU (101) throughbus (e.g. PCI-Express) (107) and Memory Bridge (103, termed also“chipset”, e.g. 975 by Intel), on the other side. As shown in FIG. 1C,the host CPU program/memory space stores the graphics applications, thestandard graphics library, and the vendor's GPU drivers.

As shown in FIGS. 1B and 1C, a prior art PC-based computing systememploys a conventional Fusion-type CPU/GPU hybrid architecture, whereina single GPU implemented on the same die as the CPU is used to support agraphics pipeline that drives an external display device. As shown, themotherboard supports the processor die, memory, a bridge with a displayinterface for connecting to a display device (106), and a PCI-expressbus. As shown, the processor die supports a CPU (1241), a GPU (1242), L2cache, buffers, an Interconnect (e.g. crossbar switch), a hypertransport mechanism and a memory controller.

As shown in FIG. 1D, the general software architecture of prior artgraphic system (200) comprises: the graphics application (201), standardgraphics library (202), and vendor's GPU driver (203). This graphicsoftware environment resides in the “program space” of main memory (102)on the host computer system. As shown, the graphic application (201)runs in the program space, building up the 3D scene, typically as a database of polygons, each polygon being represented as a set of vertices.The vertices and others components of these polygons are transferred tothe graphic card(s) for rendering, and displayed as a 2D image, on thedisplay screen.

As shown in FIG. 1E, a typical prior art PC-based computing systememploys a conventional graphics architecture employing a North memorybridge with an integrated graphics device (IGD) (103). The IGD supportsa single graphics pipeline process, and is operably coupled to a Southbridge, via a PCI-express bus, for supporting the input/output ports ofthe system. As shown, the IGD includes a video engine, a 2D engine, a 3Dengine, and a display engine.

Modem high-end GPUs have more transistors, offer at least an order ofmagnitude more of computational performance than CPUs, and draw morepower. GPU is the primary power consumer in computing system,particularly in multiple-GPU parallel systems where the powerconsumption rises manifold. Therefore it is highly desired, particularlyfor high-end graphics, to manage power consumption by turning off thepower of external GPUs to a low-power state when inactive. Powermanagement reduces overall energy consumption, prolongs battery life forportable graphics systems, reduces cooling requirements, reduces noise,and reduces operating costs for energy and cooling. Lower powerconsumption also means lower heat dissipation, which increases systemstability, and less energy use, which saves money and reduces the impacton the environment.

Thus, there is a great need in the art for a new and improved way of andmeans for practicing 3D graphics rendering processes in modemmultiple-GPU based computer graphics systems, while avoiding theshortcomings and drawbacks of such prior art methodologies andapparatus.

SUMMARY AND OBJECTS OF THE PRESENT INVENTION

Accordingly, a primary object of the present invention is to provide anew and improved method of and apparatus for practicing graphicsresource management (GRM) for 2D and 3D graphics rendering processes inmodem multiple-GPU based computer graphics systems, while avoiding theshortcomings and drawbacks associated with prior art apparatus andmethodologies.

Another object of the present invention is to provide a novel multi-GPUgraphics processing and display subsystem embodied within a PC-levelcomputing system having (i) host memory space (HMS) for storing multiplegraphics-based applications and a graphics library for generatinggraphics commands and data (GCAD) during the run-time (i.e. execution)of the graphics-based applications, (ii) one or more CPUs for executingthe graphics-based applications, and (iii) a display device fordisplaying images containing graphics during the execution of thegraphics-based applications.

Another object of the present invention is to provide such a multi-GPUgraphics processing and display subsystem comprising: a multi-GPUgraphics rendering subsystem supporting both a single-GPUmulti-threading (non-parallel) mode of graphics processing operation anda multi-GPU “application-division” parallel mode of graphics processingoperations, in order to execute graphic commands and process graphicsdata (GCAD) render pixel-composited images containing graphics fordisplay on a display device during the run-time of the multiplegraphics-based applications, and an automatic mode control module (AMCM)for automatically controlling the mode of operation of the multi-GPUgraphics processing and display subsystem during the run-time of thegraphics-based applications.

Another object of the present invention is to provide such a multi-GPUgraphics processing and display subsystem, wherein the automatic modecontrol module employs the real-time analysis of application profilesand determination of which GPUs should be assigned to handle andprocessing the stream of graphics command and data (GCAD) of particulargraphics applications running on the PC-based computing system.

Another object of the present invention is to provide such a multi-GPUgraphics processing and display subsystem, which adapts in a continuousperiodic manner to meet the changing needs of the diverse graphicsapplications such as web browsers, chat clients, IM clients, videoconferencing clients, spreadsheet programs, social network applicationsand 3D graphics applications, that are simultaneously running on thegraphics desktop environment.

Another object of the present invention is to provide such a multi-GPUgraphics processing and display subsystem, wherein an automatic modecontrol module is provided for automatically reading the name of eachgraphics application running on the computing system, and comparing thename with names of graphics-based applications registered in applicationprofile database supported within each a multi-GPU graphics processingand display subsystem.

Another object of the present invention is to provide such a multi-GPUgraphics processing and display subsystem, wherein for unknown (random)applications the automatic mode control module reads the initializationheader to determine whether the application is a DXIO or DXI 1application, and based on such determination, automatically sends thegraphics commands and data (GCAD) associated with the application to thediscrete (external) GPU or dGPU, which assignment needs to occur onlyonce at the beginning of the runtime of the graphics-based application.

Another object of the present invention is to provide a novel PC-basedcomputing system employing a multi-GPU graphics processing and displaysubsystem supporting multiple modes of graphics processing operation,which ensures the efficient use of electrical power and graphicsprocessing resources while guaranteeing that graphics-based applicationsrun at high levels of graphics performance, exhibiting sharp videos andphotos, smooth video playback, astonishing effects, and vibrant colors,photo-realism wherever intended, as well as texture-rich 3D performancein next-generation games.

Another object of the present invention is to provide a novel multi-usercomputer network supporting a plurality of client machines, wherein eachclient machine employs the multi-GPU graphics processing and displaysubsystem of the present invention based on a software-basedarchitecture.

Another object of the present invention is to provide a novel PC-basedcomputing system having a multi-GPU graphics processing and displaysubsystem that supports both a single-GPU non-parallel (multi-threading)mode of graphics processing operation and a multi-GPUapplication-division parallel mode of graphics processing operation, andwhich is capable of optimal management and conservation of electricalpower.

Another object of the present invention is to provide an Internet-basedcentral application profile database server system for automaticallyupdating, over the Internet, application profiles (APs) within the localdatabase of the multi-GPU graphics processing and display subsystem ofeach client machine registered on the network.

Another object of the present invention is to provide suchInternet-based Central Application Profile Database Server System whichensures that each multi-GPU graphics processing and display subsystem isoptimally programmed at all possible times so that it quickly andcontinuously offers users high graphics performance through its adaptivemulti-GPU graphics operation.

Another object of the present invention is to provide such anInternet-based Central Application Profile Database Server System whichsupports a Web-based Application Registration and Profile ManagementApplication, that provides a number of Web-based services.

Another object of the present invention is to provide such anInternet-based Central Application Profile Database Server System thatenables the multi-GPU graphics processing and display subsystem ofregistered client computing machines to automatically and periodicallyupload, over the Internet, Graphic Application Profiles (APs) forstorage and use within the Application Profile Database of the multi-GPUgraphics processing and display subsystem.

Another object of the present invention is to provide such anInternet-based Central Application Profile Database Server System which,by enabling the automatic uploading of APs into the multi-GPU graphicsprocessing and display subsystem, so that users of both desktop andmobile PC-based computing systems can immediately enjoy high performancegraphics on the display devices of their client machines.

These and other objects of the present invention will become apparenthereinafter and in the claims to invention.

BRIEF DESCRIPTION OF DRAWINGS OF PRESENT INVENTION

For a more complete understanding of how to practice the Objects of thePresent Invention, the following Detailed Description of theIllustrative Embodiments can be read in conjunction with theaccompanying Drawings, briefly described below:

FIG. 1A is a graphical representation of a typical prior art PC-basedcomputing system employing a conventional graphics architectureemploying a North memory bridge circuit (i.e. semiconductor chip ofmonolithic construction) driving a display, and being operably coupledto a South bridge circuit (i.e. semiconductor chip of monolithicconstruction) supporting the input/output ports of the system;

FIG. 1B is a graphical representation of a prior art PC-based computingsystem employing a conventional Fusion-type CPU/GPU hybrid architecture,wherein a single GPU implemented on the same semiconductor die as theCPU is used to support a graphics pipeline that drives an externaldisplay device, e.g. LCD panel, projection display or the like (106),via a bridge circuit, with display interface, as shown;

FIG. 1C is a graphical representation of a prior art PC-based computingsystem employing the Fusion CPU/GPU hybrid architecture of FIG. 1B,wherein the display is connected to an internal GPU via displayinterface built into a bridge connected to a memory controller;

FIG. 1D is a graphical representation of a prior art PC-based computingsystem employing a conventional graphics architecture employing a Northmemory bridge circuit (i.e. semiconductor chip of monolithicconstruction) with an integrated graphics device (IGD) (103) supportinga single graphics pipeline process, and being operably coupled to aSouth bridge circuit (i.e. semiconductor chip of monolithicconstruction) supporting the input/output ports of the system;

FIG. 1 E is a graphical representation illustrating the general softwarearchitecture of the prior art computing system shown in FIGS. 1A and 1D;

FIG. 2A is a schematic representation of a PC-based computing system ofthe present invention employing a multi-GPU graphics processing anddisplay subsystem having one internal GPU and one external GPU andsupporting single-GPU non-parallel (i.e. multi-threading) modes ofgraphics processing operation, wherein automated mode control involvesthe real-time analysis of the various graphics-based applicationsrunning on the PC-based computing system, and showing the case where theexternal GPU is used to support the graphics processing requirements ofthe high demanding graphics-based application (2) configured in thesingle-GPU non-parallel (i.e. multi-threading) mode of graphicsprocessing operation, and while the internal GPU supports the graphicsprocessing requirements of all low demanding applications (1,3,4) alsoconfigured in the single-GPU non-parallel (i.e. multi-threading) mode ofgraphics processing operation;

FIG. 2B is a schematic representation of a PC-based computing system ofthe present invention employing a multi-GPU graphics processing anddisplay subsystem having one internal GPU and two external CPUs andsupporting a single-GPU non-parallel (i.e. multi-threading) mode ofgraphics processing operation and/or a multi-GPU “application-division”parallel mode of graphics processing operation, wherein automated modecontrol involves the real-time analysis of the various graphics-basedapplications running on the PC-based computing system, and showing thecase where the external GPUs are used to support the graphics processingrequirements of high demanding graphics-based applications (2,5)configured in the multi-GPU application-division parallel mode ofgraphics processing operation, and the internal GPU supports thegraphics processing requirements of all low demanding applications(1,3,4) configured in the single-GPU non-parallel mode of graphicsprocessing operations;

FIG. 2C is a graphical representation of an exemplary desktop GUIsupported on a PC-based computing system of the present invention,depicted in FIGS. 2A and/or 2B, showing an exemplary GUI with fiveseparate windows for five graphics applications concurrently running(executing) on the CPU of the computing system, wherein the GPUvirtualization process of the present invention, involving differentGPUs potentially rendering the pixels for different application windows,effectively decouples the link between the actual GPU where theapplication runs, and the GUI window in which it is displayed;

FIG. 2D is a schematic representation of a PC-based computing system ofthe present invention employing a multi-GPU graphics processing anddisplay subsystem having one internal moderate GPU and one powerfulexternal GPU and supporting single-GPU non-parallel (i.e.multi-threading) modes of graphics processing operation, whereinautomated mode control involves the real-time analysis of the variousgraphics-based applications running on the PC-based computing system,and showing the case where all the graphics applications (1,3,4) runningon the CPU of the are of low GPU demand, and thus all graphicsprocessing requirements thereof are served by the internal GPUconfigured in the single-GPU non-parallel (multi-threading) mode ofgraphics processing operation, while the external GPU induced into itsidle state, thereby saving power by reduced power drain;

FIG. 2E is a schematic representation of a PC-based computing system ofthe present invention employing a multi-GPU graphics processing anddisplay subsystem having one moderate power internal GPU and twopowerful external GPUs and supporting both a single-GPU non-parallel(i.e. multi-threading) mode of graphics processing operation and amulti-GPU “application-division” parallel mode of graphics processingoperation, wherein automated mode control involves the real-timeanalysis of the various graphics-based applications running on thePC-based computing system, and showing the case where the internal GPUsupports the graphics processing requirements of all low demandingapplications (1,3,4,) configured in the single-GPU non-parallel mode ofgraphics processing operation, while only one external GPU is used tosupport the graphics processing requirements of a high demandinggraphics-based application 5 configured in the single-GPU non-parallelmode of graphics processing operation, while the second external GPU isinduced into its idle state, thereby reducing electrical power drain inthe computing system;

FIG. 2F is a schematic representation of a PC-based computing system ofthe present invention employing a multi-GPU graphics processing anddisplay subsystem having no internal GPU but two powerful external CPUsand supporting both a single-GPU multi-threading (non-parallel) mode ofgraphics processing operation and a multi-GPU “application-division”parallel mode of graphics processing operations, wherein automated modecontrol involves the real-time analysis of the various graphics-basedapplications running on the PC-based computing system, and showing thecase where the available graphics strength/power surpasses the needs ofthe graphics applications, and only one external GPU is used to supportthe graphics processing requirements of a graphics-based application(1,3, 4, 5) configured in the single-GPU non-parallel mode of graphicsprocessing operation, while the second external GPU is induced into itsidle state, thereby reducing electrical power drain in the computingsystem;

FIG. 3 shows a flow chart describing the steps involved the decisionprocess carried out by the automatic mode control module (AMCM) employedin the multi-GPU graphics processing and display subsystem embodied inthe PC-based computing system of the present invention;

FIG. 4A is a schematic representation of a PC-based computing system ofthe present invention employing a hybrid CPU/GPU fusion environment withsystem memory and having a multi-GPU graphics processing and displaysubsystem, wherein the AMCM and Application Profile Database (DB) areimplemented as a software module, the integrated GPU and discreteexternal CPUs on an external GPU card are interfaced with aninterconnect, and in communication with the AMCM and adapted fornon-parallel (i.e. multi-tasking) graphics processing application, andthe display is operably connected (i.e. interfaced) to the integratedGPU through the interconnect;

FIG. 4B is a schematic representation of a PC-based computing system ofthe present invention employing a hybrid CPU/GPU fusion environment withsystem memory and having a multi-GPU graphics processing and displaysubsystem, wherein the AMCM and Application Profile Database (DB) areimplemented as a software module, the integrated GPU is interfaced withan interconnect, and GPUs on an external GPU card are interfaced withthe interconnect and in communication with the AMCM and adapted fornon-parallel (i.e. multi-tasking) graphics processing application, andthe display is operably connected to the GPU on the external graphicscard;

FIG. 4C is a schematic representation of a PC-based computing system ofthe present invention employing a CPU with system memory and having amulti-GPU graphics processing and display subsystem, wherein the AMCMand Application Profile Database (DB) are implemented as a softwaremodule, an IGD residing on north bridge is in communication with theAMCM, the GPUs on an external graphic card(s) are in communication withthe AMCM and adapted for application-division parallelism, and thedisplay is connected either to a primary GPU (IGD) or a primary GPU oneof the external graphics cards;

FIG. 4D is a schematic representation of a PC-based computing system ofthe present invention employing a CPU with system memory and a North(Memory) Bridge and having a multi-GPU graphics processing and displaysubsystem, wherein the AMCM and Application Profile Database (DB) areimplemented as a software module, an IGD residing on South Bridge is incommunication with the AMCM, the GPUs on external graphic card(s) are incommunication with the AMCM and adapted for application-divisionparallelism, and the display is connected either to the IGD or a primaryGPU on an external graphics card;

FIG. 4E is a schematic representation of a PC-based computing system ofthe present invention employing a CPU with system memory and a North(Memory) Bridge and South Bridge and having a multi-GPU graphicsprocessing and display subsystem, wherein the AMCM and ApplicationProfile Database (DB) are implemented as a software module, the GPUsresiding on the dual external graphics cards are in communication withthe AMCM and adapted for application-division parallelism, and thedisplay is connected to the primary GPU on the external graphics card,and power savings mode can be exercised on the external GPUs; and

FIG. 5A is a schematic representation of Central Application ProfileDatabase (DB) Server System, implemented on a multi-user computernetwork supporting a plurality of client machines, wherein each clientmachine embodies multi-GPU graphics processing and display subsystemaccording to the present invention, and supporting an ApplicationProfile (AP) Database (DB) in the subsystem, and periodically updatingand distributing Application Profiles to all client machines registeredon the network for such services.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS OF THE PRESENTINVENTION

Referring now to FIGS. 2A through 5A in the accompanying Drawings, thevarious illustrative embodiments of the computing system of the presentinvention will be described in great technical detail, wherein likeelements will be indicated using like reference numerals. The primarymotivation of present invention is to better manage the use ofelectrical and graphics-processing power in modern PC computer systemenvironments where running diverse applications simultaneously in amulti-tasking environment is commonplace.

Power management turns off the power of external GPU to a low-powerstate when inactive. It is desired particularly for graphics because ofthe high power consumption of high-end GPUs. Power management reducesoverall energy consumption, prolongs battery life for portable graphicssystems, reduces cooling requirements, reduces noise, and reducesoperating costs for energy and cooling. Lower power consumption alsomeans lower heat dissipation, which increases system stability, and lessenergy use, which saves money and reduces the impact on the environment.

The multi-GPU graphics processing and display subsystem of the presentinvention is able to assign graphics tasks in real time to the bestavailable graphics resource(s) available on a multi-GPU graphicsprocessing and display subsystem based on power, performance and featureconsiderations, with no need for additional hardware. If high-endgraphics power is needed for applications like DirectX 11,high-resolution 3D gaming, then the subsystem will automatically assignthe job to the discrete GPU supported on the subsystem. If not, then thediscrete GPU is automatically induced into its idle power mode, causingthe heat transfer level to drop, fan speed slow down and GPU utilizationdecrease down to zero, resulting in a green, power-efficient,long-lasting graphics processing and display system.

In general, the PC-based computing system of the present invention,regardless of particular implementation, is capable of parallelizing theoperation of one or more internal GPUs supported internally on themotherboard of the system, and one or more external GPUs supported onone or more external graphics cards. Typically, the computing systemcomprises the following components: CPU memory space (e.g. RAM) forstoring (i) at least one operating system (OS) program supporting aGUI-based desktop windows environment with multiple display windows asshown in FIG. 2C, (ii) multiple graphics-based applications and graphicslibraries (e.g. OpenGL or DirectX) for generating graphics commands anddata (GCAD) during the execution of the graphics-based applications, and(iii) vendor drivers for internal and external GPUs supported within thesystem; one or more CPUs for executing the OS and its desktop windowsenvironment described above, and multiple graphics applicationssimultaneously on the desktop environment of the computing system, and amemory controller for controlling the CPU's and GPUs access to the CPUmemory space; one or more external graphics cards supporting one or moreexternal GPUs; hard-drive or persistent memory storage; one or moreinternal GPUs which may be realized in the form of an IGD or GPUrealized in a hybrid GPU/CPU chip environment, or a multi-core CPUenvironment; a multi-GPU graphics processing and display subsystemsupporting a plurality of graphic processing pipelines (GPPLs)implemented using multiple internal GPUs, and/or multiple external GPUs,and supporting both a single-GPU non-parallel (i.e. multi-threading)mode of graphics processing operation and a multi-GPU“application-division” parallel mode of graphics processing operation,in order to execute graphic commands, process graphics data, and renderpixel-composited images containing graphics for display on a displaydevice during the run-time of the graphics-based applications, whereinthe display device is connectable to at least one the external orinternal GPUs functioning as the designated primary GPU; and anautomatic mode control module (AMCM) for automatically andsimultaneously analyzing—in real-time—the various multiple graphicsapplications that are likely to be running on different threads in a PCcomputing environment, and which contribute to the collective/composite“graphics environment” that is supported at any instant on the PCcomputing system. The AMCM also controls the mode of operation of themulti-GPU graphics processing and display subsystem (i.e. platform) inresponse to such real-time graphics application analysis.

During system operation, the AMCM balances the graphics load betweeninternal GPU and single or multiple external GPUs. In general, theinternal GPU excels in advanced power-efficiency, built-in mediafeatures, and rather moderated graphics processing capabilities. Theinternal GPU, called also IGP (Integrated Graphics Processor), or IPG(Intel Processing Graphics), can be found in various architectures andlocations of computing systems, including in North Bridge or in FusedCPU/GPU chip (e.g. Sandy Bridge by Intel). The external GPU, termed alsoDiscrete GPU (dGPU) is typically more powerful, but is also the primarypower consumer in computing systems.

The real-time analysis of multiple graphics applications running on thePC computing system by AMCM is intended to estimate the graphics load ofthose applications. The load considerations are based on followingparameters: (i) all 2D graphics applications, as well as mediaapplications, are considerably less demanding than 3D graphicsapplications (such as video games), and thus are candidates to run oninternal GPU; (ii) the estimated load of 3D applications is based ongraphics parameters that are typically set during initialization phase,such as anti-aliasing, Resolution, etc.; (iii) the above factors ofknown applications can be gathered either offline or in runtime andsaved in a data base (DB) of application profiles (APs), held by AMCM.These application profiles (APs) are verified by measuring actual runtimes, and kept updated in the DB for successive runs.

The multi-GPU graphics processing and display subsystem automaticallysupports both a single-GPU non-parallel (i.e. multi-threading) mode ofgraphics processing operation and/or a multi-GPU “application-division”parallel mode of graphics processing operation, to optimize the use ofelectrical power consumption and computing resources (graphics power),as needed for each application running on the computing system. Duringmaximal application load, while enabled and running a 3D application,all external GPUs in the system are enabled and running in parallel,while applications are divided among GPUs, such that the heavy graphicsapplication run on dGPUs, and other applications run on internal GPUs.In general, 3D graphics applications based on OpenGL and DirectXgraphics libraries are considered to be heavier than 2D and mediaapplications, in terms of the graphics processing operations required toexecute graphics commands and data (GCAD) streams issuing from suchapplications.

FIG. 2A shows a PC-based computing system of the present inventionemploying a multi-GPU graphics processing and display subsystem havingone internal GPU and one external GPU and supporting single-GPUnon-parallel (i.e. multi-threading) modes of graphics processingoperation. In this illustrative embodiment, the automated mode controlmodule (AMCM) in the PC-based computing system performs real-timeanalysis of the various graphics-based applications running on thecomputing system. Also, in FIG. 2, the case is shown where the externalGPU is used to support the graphics processing requirements of the highdemanding graphics-based application (2) configured in the single-GPUnon-parallel (i.e. multi-threading) mode of graphics processingoperation, while the internal GPU supports the graphics processingrequirements of all low demanding applications (1,3,4) also configuredin the single-GPU non-parallel (i.e. multi-threading) mode of graphicsprocessing operation. As such, the graphics command and data (GCAD)stream from the lighter graphics applications 1,3 and 4 are assigned(i.e. distributed) to the internal GPU configured in the single-GPUnon-parallel (i.e. multi-threading) mode of graphics processingoperation. The processing power of external GPU is dedicated exclusivelyto the GCAD stream from high demanding Application 2. In this case, theexternal GPU is also configured in the single-GPU non-parallel (i.e.multi-threading) mode of graphics processing operation. The decision iscarried out in real-time by AMCM, using the process specified in FIG. 3,and the GCAD streams from the graphics applications are automaticallyredirected to the GPU resources, accordingly. In this embodiment, thedisplay is permanently connected to the internal GPU, therefore eachimage frame generated in dGPU must be transferred to the internal GPUfor merging with other graphics images of the various applications, tocomposite a complete desktop (GUI) image which is then moved to thedisplay device display.

FIG. 2B shows a PC-based computing system of the present inventionemploying a multi-GPU graphics processing and display subsystem havingone internal GPU configured in a single-GPU non-parallel mode ofgraphics processing operation, and two external GPUs configured in anmulti-GPU application-division parallel mode of graphics processingoperation. In this case, the graphics processing power of the externalGPU is dedicated exclusively processing the GCAD stream of the highdemanding applications, 2 and 5. The internal GPU multi-processes theGCAD streams from all low demanding applications, 1, 3 and 4.

Graphics virtualization according to the present invention multiplexesphysical hardware by presenting each GPU with a virtual device andcombining its respective operations in the graphics system in a way thatutilizes native hardware while preserving the illusion that eachapplication has a complete stand-alone device. This virtualizationprinciple is demonstrated in FIG. 2C, showing possible screen look forimages of graphics applications of the given example. Each application'simage is located in a separate window. In the user's eyes, GPUvirtualization decouples the link between the actual GPU where theapplication runs, and the window it shows.

The manner in which power management of AMCM turns off the power ofexternal GPU to a low-power state when inactive, is shown in FIGS. 2Dand 2E.

FIG. 2D shows a PC-based computing system of the present inventionemploying a multi-GPU graphics processing and display subsystem havingone internal moderate GPU and one powerful external GPU and supporting,each configured in a single-GPU non-parallel (i.e. multi-threading)modes of graphics processing operation. In FIG. 2D, automated modecontrol involves the real-time analysis of the various graphics-basedapplications running on the PC-based computing system, and showing thecase where all the graphics applications (1,3,4) running on the CPU areof low GPU processing demand, and thus all graphics processingrequirements thereof are served by the internal GPU configured in thesingle-GPU non-parallel (multi-threading) mode of graphics processingoperation, while the external GPU induced into its idle state, therebysaving power by reduced power drain. Since the available graphicsstrength of the GPUs surpasses or exceeds the need of the graphicsapplications, the GCAD stream from these applications are distributed insuch a way that one GPU remains inactive, i.e. turned down to low-powerstate, to conserve electrical power/energy.

FIG. 2E shows a PC-based computing system of the present inventionemploying a multi-GPU graphics processing and display subsystem havingone moderate power internal GPU configured in a single-GPU non-parallel(i.e. multi-threading) mode of graphics processing operation, and twopowerful external GPUs configured in a multi-GPU “application-division”parallel mode of graphics processing operation. In FIG. 2E, automatedmode control involves the real-time analysis of the variousgraphics-based applications running on the PC-based computing system,and showing the case where the internal GPU supports the graphicsprocessing requirements of all low demanding applications (1,3,4)configured in the single-GPU non-parallel mode of graphics processingoperation, while only one external GPU is used to support the graphicsprocessing requirements of a high demanding graphics-based application 5configured in the single-GPU non-parallel mode of graphics processingoperation, while the second external GPU is induced into its idle state,thereby reducing electrical power drain in the computing system.

The presence of internal GPU is not a requirement when practicing theprinciples of the present invention. Resource management by way ofapplication division can be performed on external GPUs, in the absenceof an internal GPU or IGD. This inventive concept is illustrated in FIG.2F, where there is shown, a PC-based computing system employing amulti-GPU graphics processing and display subsystem having no internalGPU, but two powerful discrete external GPUs capable of supporting botha single-GPU multi-threading (non-parallel) mode of graphics processingoperation and a multi-GPU “application-division” parallel mode ofgraphics processing operation. In this embodiment, automated modecontrol involves the real-time analysis of the various graphics-basedapplications running on the PC-based computing system. In FIG. 2F, thecase shows where the available graphics strength/power surpasses theneeds of the graphics applications, and only one external GPU is used tosupport the graphics processing requirements of a graphics-basedapplication (1,3,4,5) configured in the single-GPU non-parallel mode ofgraphics processing operation, while the second external GPU is inducedinto its idle state, thereby reducing electrical power drain in thecomputing system.

Based on the logical decision process carried out by AMCM, the GCADstream from each graphics application is sent to external or internalGPU(s). The flowchart of FIG. 3 specifies the decision process carriedout by the AMCM in the multi-GPU graphics processing and displaysubsystem of each PC-based computing system of the present invention.This process is invoked once for each graphics-based applicationexecuted by the CPU of the computing system, and it is done soautomatically at the beginning of the launching of the graphics-basedapplication. Based on the results of this process, the stream of CGADfrom the application is (re)directed to the indicated GPU within themulti-GPU graphics processing and display subsystem of the computingsystem.

As indicated at Block 31 in FIG. 3, the first step involves readingbasic information found in application's header.

As indicated at Block 32 in FIG. 3, the name of the graphics applicationis looked up in the Application Profiles (AP) Data Base (DB). In theillustrative embodiment, the AP-DB maintains two different lists ofgraphics application profiles (APs), namely: (1) a first list of allgraphics applications having relatively light graphics processing loadrequirements (e.g. email applications, spreadsheets, IM chat clients,work-processing applications, slide presentation programs, web browsersrunning Flash plug-ins etc) whose GCAD stream should be sent to aninternal GPU (e.g. IGD or hybrid CPU/GPU chip) or external GPUconfigured for a non-parallel (i.e. multi-tasking) mode of graphicsprocessing operation, as the case may require for power conservationreasons; and (2) a second list of all graphics application havingrelatively high graphics processing load requirements (e.g. 3D graphicsapplications) whose GCAD stream should be sent to a single external GPUconfigured in a non-parallel (i.e. multi-tasking) mode of graphicsprocessing operation, or to multiple external GPUs configured in the“application-division” parallel mode of graphics processing application,as described herein.

As indicated at Block 33 in FIG. 23, the application name is found inthe AP-DB, then the application profile is retrieved from ApplicationProfile DB maintained with the multi-GPU graphics processing and displaysubsystem. Otherwise, as Block 34, the application name is searched forin the 3D class (OpenGL or DirectX application). As indicated at Block35, if the application is not a 3D graphics application, then its GCADstream is sent to internal GPU.

At Block 36 in FIG. 3, 3D applications, not previously known, areanalyzed for initialization parameters (e.g. AA, resolution), the loadis coarsely estimated at Block 37, and accordingly decision is made forinternal GPU at Block 35, or external GPU at Block 39.

FIGS. 4A through 4E provide illustrative examples of variousarchitectures in which graphics resources are dynamically managed usingthe novel principles of the present invention using a multi-GPU graphicsprocessing and display subsystem supporting a single-GPU non-parallelmode of graphics processing operation and/or multi-GPU“application-division” parallel mode of graphics processing operation.

FIG. 4A shows a PC-based computing system of the present inventionemploying a hybrid CPU/GPU fusion environment with system memory andhaving a multi-GPU graphics processing and display subsystem, whereinthe AMCM and Application Profile Database (DB) are implemented as asoftware module, the integrated GPU and discrete external GPUs on anexternal GPU card are interfaced with an interconnect, and incommunication with the AMCM and adapted for non-parallel (i.e.multi-tasking) graphics processing application, and the display isoperably connected (i.e. interfaced) to the integrated GPU through theinterconnect.

FIG. 4B shows a PC-based computing system of the present inventionemploying a hybrid CPU/GPU fusion environment with system memory andhaving a multi-GPU graphics processing and display subsystem, whereinthe AMCM and Application Profile Database (DB) are implemented as asoftware module, the integrated GPU is interfaced with an interconnect,and GPUs on an external GPU card are interfaced with the interconnectand in communication with the AMCM and adapted for non-parallel (i.e.multi-tasking) graphics processing application, and the display isoperably connected to the GPU on the external graphics card.

FIG. 4C is a schematic representation of a PC-based computing system ofthe present invention employing a CPU with system memory and having amulti-GPU graphics processing and display subsystem, wherein the AMCMand Application Profile Database (DB) are implemented as a softwaremodule, an IGD residing on north bridge is in communication with theAMCM, the GPUs on an external graphic card(s) are in communication withthe AMCM and adapted for application-division parallelism, and thedisplay is connected either to a primary GPU (IGD), or alternatively toa primary GPU one of the external graphics cards.

FIG. 4D is a schematic representation of a PC-based computing system ofthe present invention employing a CPU with system memory and a North(Memory) Bridge and having a multi-GPU graphics processing and displaysubsystem, wherein the AMCM and Application Profile Database (DB) areimplemented as a software module, an IGD residing on South Bridge is incommunication with the AMCM, the GPUs on external graphic card(s) are incommunication with the AMCM and adapted for application-divisionparallelism, and the display is connected either to the IGD, oralternatively to a primary GPU on an external graphics card.

FIG. 4E shows a PC-based computing system of the present inventionemploying a CPU with system memory and a North (Memory) Bridge and SouthBridge and having a multi-GPU graphics processing and display subsystem.In this illustrative embodiment, the AMCM and Application ProfileDatabase (DB) are implemented as a software module, the GPUs residing onthe dual external graphics cards are in communication with the AMCM andadapted for application-division parallelism, and the display isconnected to the primary GPU on the external graphics card. The powersavings mode can be exercised on the external GPUs, and power savingsmode can be exercised on one or more GPUs on the external graphicscards, according to graphics load.

FIG. 5A shows an automated way of updating the application profiles inthe AP DBs of client machines. As shown, the Central Application ProfileDatabase (DB) Server System of the illustrative embodiment comprises acluster of Web (http) servers, interfaced with a cluster of applicationservers, which in turn are interfaced with one or more database servers(supporting RDBMS software), well known in the art. The CentralApplication Profile Database (DB) Server System would support aWeb-based Application Registration and Profile Management Application.

Using the Central Application Profile Database (DB) Server System of thepresent invention, it is now possible to automatically and periodicallyupload, over the Internet, Graphic Application Profiles (APs) within theDB of the multi-GPU graphics processing and display subsystem ofregistered client machines. By doing so, graphic application users (e.g.gamers) can immediately enjoy efficient resource management, withouthaving to develop an application profile based on many hours of actualuser-system interaction.

For Automatic AP management service subscribers, the multi-GPU graphicsprocessing and display subsystem would preferably run an algorithm thatuses the most recently downloaded expert AP loaded into its AMCM, untilthe next automated update occurs.

Applicants have disclosed how using the technology of the presentinvention, it is possible for next generation personal computing systemsto dynamically balance the advanced power-efficient, built-in mediafeatures of modem-day processor graphics with the high-end, DirectX 113D performance features of discrete GPUs. At the same time, the presentinvention significantly reduces the power drain of traditionalentertainment desktops.

The GPU virtualization solution of the present invention is able toassign tasks in real time to the best available graphics resource basedon power, performance and features considerations, with no need foradditional hardware, providing a seamless visual experience where it isnot necessary to choose between the amazingly rich media features suchas HD playback and powerful video transcoding, and the high-end 3Dgraphics functionality and performance of a discrete GPU.

While the illustrative embodiments of the present invention have beendescribed in connection with various PC-based computing systems,including desktop and mobile computers, it is understood that thatmulti-GPU graphics processing and display subsystems, systems andprocesses of the present invention can also be used in mobile computingdevices, video game consoles and systems, e-commerce and PUS displaysand the like.

It is understood that the multi-GPU graphics processing and displaytechnology employed in computer graphics systems of the illustrativeembodiments may be modified in a variety of ways which will becomereadily apparent to those skilled in the art of having the benefit ofthe novel teachings disclosed herein. All such modifications andvariations of the illustrative embodiments thereof shall be deemed to bewithin the scope and spirit of the present invention as defined by theClaims to Invention appended hereto.

What is claimed is:
 1. A power management device for a computing system,the computing system comprising: a multi-GPU graphics processing anddisplay subsystem having at least one internal GPU and at least oneexternal GPU and supporting multi-GPU application-division parallelmodes of graphics processing in order to execute graphic commands andprocess graphics data and render pixel-composited images containinggraphics for display on a display device during the run-time of themultiple graphics based applications; and an automatic mode controlmodule for automatically controlling the mode of operation of themulti-GPU graphics processing and display subsystem during the run timeof the multiple graphics-based applications so as to ensure efficientpower management and graphics processing resource allocation; whereinthe automatic mode control module employs real-time detection ofindividual application profiles and determines which GPU or GPUs in themulti-GPU graphics processing and display subsystem should be assignedto process the stream of graphics command and data of particulargraphics applications running on the computer system; and wherein for anunknown graphics based application that has not been previously profiledfor graphics processing requirements, the automatic mode control moduleautomatically reads an initialization header of the unknown graphicsbased application to determine whether the unknown graphics basedapplication is a low graphics based application or a high graphics basedapplication, and based on such determination automatically send thegraphics commands and data associated with the unknown graphics basedapplication to the at least one internal GPU or the at least oneexternal GPU.
 2. The power management device of claim 1, wherein thepower management module puts the external GPU into an idle state in theevent the real-time detection of an individual application profileindicates a low graphics load application.
 3. The power managementdevice of claim 1, wherein the power management module, in the eventthat the real-time detection of an individual application profileindicates a high graphics load application, one of: puts the internalGPU into an idle state or puts neither GPU into an idle state.
 4. Thepower management device of claim 1, wherein the computing system is oneof: a mobile computing device or a desktop personal computer.
 5. Thepower management device of claim 1, wherein the automatic mode controlmodule includes two databases, a first database for storing graphicapplication profiles having light graphics processing load requirementsand a second database for storing graphic application profiles havinghigh graphics processing load requirements.
 6. The power managementdevice of claim 1, wherein the multi-GPU graphics processing and displaysubsystem updates graphic application profiles by automatically andperiodically uploading over the Internet, graphic application profilesfor storage and use within the automatic mode control module database.7. The power management device of claim 1, wherein the computing systemincludes two external GPUs and one internal GPU, and wherein the powermanagement module puts one or more of the two external GPUs into an idlestate in the event the real-time detection of an individual applicationprofile indicates a low graphics load application.
 8. A method ofmanaging power consumption in a computing system, wherein the computingsystem comprises: a multi-GPU graphics processing and display subsystemhaving at least one internal GPU and at least one external GPU andsupporting multi-GPU application-division parallel modes of graphicsprocessing in order to execute graphic commands and process graphicsdata and render pixel-composited images containing graphics for displayon a display device during the run-time of the multiple graphics basedapplications; and an automatic mode control module for automaticallycontrolling the mode of operation of the multi-GPU graphics processingand display subsystem during the run time of the multiple graphics-basedapplications so as to ensure efficient power management and graphicsprocessing resource allocation; the method comprising: the automaticmode control module real-time detection of individual applicationprofiles and determines which GPU or GPUs in the multi-GPU graphicsprocessing and display subsystem should be assigned to process thestream of graphics command and data of particular graphics applicationsrunning on the computer system; and for an unknown graphics basedapplication that has not been previously profiled for graphicsprocessing requirements, the automatic mode control module automaticallyreading an initialization header of the unknown graphics basedapplication to determine whether the unknown graphics based applicationis a low graphics based application or a high graphics basedapplication, and based on such determination automatically send thegraphics commands and data associated with the unknown graphics basedapplication to the at least one internal GPU or the at least oneexternal GPU.